9303966 Harris In this collaborative research, PIs will develop and evaluate criteria for recognizing stratigraphic sequences in outer-shelf and slope carbonate environments. Recognition of sequence boundaries in these settings is problematic because typical boundary criteria are not applicable--exposure events are absent and stratal geometries are difficult to extract from outcrop-scale exposures. PIs will combine stratigraphic, sedimentologic and biostratigraphic study of Ordovician and Silurian strata in the U.S. Great Basin to develop a sequence model; the sequences will be traced along dip and strike transects to evaluate changes in criteria usable in identifying sequence boundaries. This work will contribute not only to understanding Paleozoic history of the Great Basin, but also to developing sequence stratigraphic models for deeper-water carbonate units. Results will have use in both academia and industry.